摘要
冀北滦平张家沟门村大北沟组上部首次发现凝灰岩和凝灰质砂岩层 ,其中单颗粒锆石SHRIMPU_Pb年龄为 133.9± 2 .5Ma、130 .1± 2 .5Ma,并新测得井上村东张家口组顶部流纹质强熔结凝灰岩单颗粒锆石SHRIMPU_Pb年龄为 135 .4± 1.6Ma。综合研究及对比表明 ,滦平盆地含热河生物群岩系层序较为齐全 ,热河生物群应萌发于135Ma ;大北沟组大店子组界线年代为 130Ma。该界线年代的确定有助于侏罗白垩系界线年代的研究。
The recently discovered bedded tuff and tuffaceous sandstone within the Dabeigou Formation in Luanping basin of northern Hebei were dated by SHRIMP zircon U-Pb technique at 133.9±2.5 Ma and 130.1± 2.5 Ma respectively. The SHRIMP zircon U-Pb age of 135.4±1.6 Ma for the top tufflava of the Zhangjiagou Formation at eastern Jingshang Village was also obtained. A comprehensive study indicates that a complete Jehol biota-bearing succession is deposited in Luanping basin of northern Hebei, and that 135 Ma is the lowest chronohorizon from which Jehol biota appeared. The authors hold that the boundary between Dabeigou Formation and Dadianzi Formation is 130 Ma in age, the data is helpful to the study of the boundary between Jurassic and Cretaceous.
出处
《岩石矿物学杂志》
CAS
CSCD
北大核心
2003年第3期237-244,共8页
Acta Petrologica et Mineralogica
基金
国土资源部地质大调查资助项目 (DKD2 0 0 10 19)
国土资源部国际合作与科技司资助项目 (2 0 0 0 10 40 4)
